1. Field of the Invention
This invention relates in general to integrated circuits and more specifically to noise isolation between circuit blocks in an integrated circuit chip.
2. Description of the Related Art
Increasingly, integrated circuit chips have different types of circuit blocks, such as analog and digital circuit blocks. Without proper noise isolation, noise generated by digital circuit blocks can interfere with more sensitive circuit blocks, such as phase locked loops and low noise amplifier circuits. Conventional noise isolation between different types of circuit blocks requires bias. Bias, however, is prone to contamination and thus compromises noise isolation efficiency.
Thus, there is a need for improved noise isolation between circuit blocks in an integrated circuit chip.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.